The Center for Education and Drug Abuse Research (CEDAR) has two overarching objectives: l) delineate the vulnerability to substance abuse; and, 2) clarify the developmental pathways linking identified biobehavioral vulnerability to a drug abuse outcome. Toward these objectives, the results of this ongoing multidisciplinary prospective investigation will inform about l) the factors which differentiate high from low risk individuals; 2) reveal variants or subtypes of substance abuse vulnerability; 3) elucidate the environmental risk factors which interact with vulnerability to affect the developmental trajectory to either a good or poor outcome; and, 4) ascertain whether the identified vulnerability to substance abuse is specific to only this disorder. A total of 1,000 families will be recruited for longitudinal study. Adult male and female probands are ascertained who have a son or daughter who is between 10-12 years of age. These offspring, defined as the index case, are studied extensively at baseline to characterize genetic, biochemical, cognitive, behavioral, familial and social environment processes. They will be prospectively followed up on seven occasions until they attain 30 years of age. The sample will be equally represented by male and female index cases and distributed in a 70:30 ratio between Caucasian and African-American families when recruitment is completed. In addition, the sibship is also studied and tracked to outcome at age 30. Finally, the first degree relatives of the probands and their spouses are also characterized with respect to drug/alcohol and psychiatric history. The 1,000 families are organized into four equal size groups: l) male SA probands with a male index offspring; 2) male normal controls with a male index offspring; 3) female SA probands with a female index offspring; and, 4) female normal controls with a female index offspring. Whereas the main thrust of CEDAR is to elucidate drug abuse etiology, the products of this comprehensive multidisciplinary research program will point to areas of intervention which can potentiate prevention by targeting specific interventions to particular aspects of vulnerability in context of the social environment.